GB281548A - Sparking plug for internal combustion engines - Google Patents

Abstract

281,548. Wolff, F. June 7, 1927. Sparking-plugs.-The insulation is in two portions, that nearer to the combustion chamber being of heat-resisting material such as porcelain, glass, mica, quartz, steatite or fibre, and the outer portion 6 being of plastic material such as artificial resin, which is forced into position under high temperature and pressure. The metal casing may also be in two portions, the portion 2 having an internal flange 5 which serves as a bearing for the insulating materials, but through the middle of which the heating-resisting member projects into intimate contact with the plastic material. Indentations 7, 10, 11 may be provided to improve the contact and promote gas-tightness. In a modification the flange 5 is omitted, and the casing is in one piece with a dovetailed recess in its internal wall, the plastic material filling this recess and interlocking with projections on the inner insulator. In a further modification the plastic material encloses a sleeve into which the end of the conducting cable may be inserted, and which at its inner end is in electrical contact with the central conductor passing through the ceramic insulator.